Effect of forage presentation on feed intake behaviour in stabled horses

In some stabled horses, the lack of foraging opportunity leads to a reduction in chewing time with consequent negative impacts on the digestive system and potentially development of stereotypies. This study aimed to compare the effect of four types of haynets on feed intake behaviour in stabled horses. Feed intake behaviour (intake time, bite rate, chews/kilogram, chews/minute) was measured in 12 horses (age 13 ± 4 yrs; BW 585 ± 62 kg) using four types of haynets (Eliminet 25 mm mesh, Furlong 30 mm, Haylage net 30 mm, Original 'Large' 75 mm) in a 4 × 4 Latin Square Design. Horses were provided with their daily forage intake via each haynet for a 10-day period and forage intake measurements were taken at the beginning, middle and end of each period to account for acclimatisation to the haynets. Data was analysed using ANOVA and is presented as means ± standard error. The 'Large' haynet recorded more chews per minute (66 ± 1.1 versus 60 ± 1.0 chews/min, p < 0.01) compared to other haynets due to a reduced bite rate (17 ± 1.7 bites/kg versus 28 ± 1.6 bites/min, p < 0.001). The Eliminet (smallest mesh) only showed a weak trend in reduced intake in grams per minute translating to a significantly increased intake time per 1 kg of hay compared to the Large haynet (Eliminet 33 min, Furlong 29 min, Haylage 28 min, Large 25 min; p < 0.01) when excluding acclimatisation data (beginning). Overall, however, all smaller holed haynets (25-30 mm) were equally successful in slightly slowing feed intake down with an increased intake time of around 5 min/kg compared with the 'large-holed' haynet (75 mm). Night observations (n = 6) showed no difference in the time to finish eating between the haynets but did show that feeding time was spread slightly more across the night with the smaller mesh nets. Most horses (67% of observations) had eaten all their forage or no longer returned to the nets (6.5 ± 1 kg) after 22:30 at night.